This year, they plan to hold a May 4 Survival Race, the May 5 Zombie Race, and a second Survival Race on Sept. 7 — all at the 4H camp off Sound Avenue, according to Mr. Villepique.

The Survival Race is a 5K run in which participants will tackle a number of obstacles and mud puddles.

The Zombie Race is a 5K run in which participants must allude people dressed as zombies who will try to capture flags worn at the runners’ waists, said Mr. Villepique. Racers have a belt with four flags, like in flag football, and if the zombies capture all four flags, that runner is out of the race and turns into a zombie.

“The difference between the two is that the Survival Race is more of an athletic type event while the Zombie Race is more of an entertainment event,” Mr. Villepique said.

The zombies are given costumes and are screened, he said. The zombies cannot touch runners and are instructed not to scare people to the point they are actually frightened, especially children, he added.

“It’s not like we have zombies wandering in the forest,” Mr. Villepique said. “We have designated areas that we call a zombie hoard. And then there are managers of each hoard, so, say, there may be 10 zombies in a hoard, and then there is one manager in the hoard who oversees the conduct of each group of zombies, to make sure they follow our code of conduct.”

When the group appeared at the April 11 Town Board work session, board members initially said an event of this size should have been proposed much earlier, and Mr. Walter suggested it might need a mass gathering permit from the county, and that it had already been submitted too late for that.

But race organizers said they would keep the attendance below the 5,000 attendance figure for which a mass gathering permit would be required.

Riverhead Police Lieutenant Richard Boden also said that last year’s event did not cause traffic problems.

A main complaint last year was that the Survival Race used Terry Farm Road, which is a private road. The race organizers say they will not use that road this year.

While the Survival Race may have about 4,000 runners, the runners start in waves of about 100 each half hour, so there is never a point where all 4,000 runners are entering or leaving the site at the same time, Mr. Villepique said.

The Riverhead Town Board on Thursday met with organizers of the “Survivor Race” 5K who are hoping to hold an event in May similar to one they ran last September in Riverhead.

The event is planned for property off Sound Avenue this spring, with another in September

But Supervisor Sean Walter warned that the organizers should have approached the Town Board months ago about the event, which could draw up to 5,000 people. Events of that size require a county mass gathering permit, which isn’t that easy to come by, Mr. Walter explained.

More than 3,000 runners participated in the first-ever Survival Race 5K mud run to take place at the 4-H Camp in Riverhead Saturday.

One event staffer said it was the largest number of participants in two years of running the race in various locations.

“It was good,” said William Waller of East Patchogue, who ran the race with his wife, Michelle, and friends. “I would do it again, but I would like the mud pit to be longer.”

Mr. Waller said his crew ran the race to raise money for Children’s Heart Foundation of New York City.

The 5K mud run course was created by Dean Del Prete of Westhampton, also owner of Cousins Paintball in Calverton.

“This is crazy,” Mr. Del Prete said Saturday morning. “I love watching people have fun. It’s a great way to make a living.”

In the first wave of the day, Dan Broadbent of Center Moriches came in at 26:08 and the first female was Amanda McDonnell with a time of 31 minutes.

But the races were more about having fun and getting muddy than they were about results.

One participant yelled “don’t you realize this is gross,” as she hit the mud pit, which was near the finish line.

After cleaning himself off in a puddle and under the spray of an irrigation pipe, Justin Deiter, 29, of Babylon said, “It was fun. I do tough mudder races all over the world. They are a bit more involved, since they were created by the military.”

The last event Survival Race, held in Dallas, had 1,700 participants. The next race is in Toledo, Ohio on Sept. 29.

Despite the high volume of participants, there were no traffic problems reported on Sound Avenue. Riverhead Volunteer Ambulance Corp EMT Tommy Cappiello said there were only minor injuries, mostly bee stings.